Updated punch description.

Author: 5cript

README.md

@@ -182,7 +182,8 @@ Options are:
     - [After deoverlap](#after-deoverlap)
     - [interval\_tree deoverlap\_copy()](#interval_tree-deoverlap_copy)
     - [interval\_tree punch(interval\_type const\& ival)](#interval_tree-punchinterval_type-const-ival)
-    - [After punching (with \[0, 50\])](#after-punching-with-0-50)
+    - [Before punching (closed intervals)](#before-punching-closed-intervals)
+    - [After punching (with \[-10, 60\])](#after-punching-with--10-60)
     - [interval\_tree punch()](#interval_tree-punch)
     - [bool empty() const noexcept](#bool-empty-const-noexcept)
     - [iterator begin()](#iterator-begin)
@@ -367,13 +368,19 @@ Same as deoverlap, but not inplace
 
 ---
 ### interval_tree punch(interval_type const& ival)
-Removes all intervals from `ival` and produces a tree that contains the remaining intervals.
-**The tree must be deoverlapped, or the result is undefined.**
-`ival` is expected to encompass the entire interval range.
+Cuts the intervals of the tree out of the given interval. Like a cookie cutter cuts out of dough.
+This will return a new interval_tree containing the gaps between the intervals in the tree and the given interval.
+Closed (and closed adjacent) intervals are treated as exclusive on the borders. [0,5][6,10] will not produce another interval between 5 and 6 as they are considered within the intervals and nothing fits inbetween.
+Open intervals will not behave like this, so (0,5)(6,10) will produce a new interval (5,6).
+
+**IMPORTANT! The tree must be deoverlapped, or the result is undefined.**
+`ival` can be any subrange of the tree, including encompassing the whole tree.
 
 **Returns**: A new interval_tree containing the gaps.
-### After punching (with [0, 50])
-![AfterPunch](https://cloud.githubusercontent.com/assets/6238896/24613645/2dbf72e8-1889-11e7-813f-6d16fe0ad327.png)
+### Before punching (closed intervals)
+![BeforePunch](https://private-user-images.githubusercontent.com/6238896/471147224-5c631e00-dea4-4b75-a3bf-6fdd8ec1440b.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.P5zLeXg0-9bd20Thj6pfq_WxriMn4GC_lDSLzzGKMbw)
+### After punching (with [-10, 60])
+![AfterPunch](https://private-user-images.githubusercontent.com/6238896/471147227-5c226d1d-d544-4a43-89a4-b3545145107d.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.Infe9i281LDOEC5GeBFuLHVE6Xjqw7KvcUo-gv3hjpk)
 
 ---
 ### interval_tree punch()